Phospholipids, such as lecithin, are amphipathic compounds in that they consist of both hydrophobic and hydrophilic groups or regions within the same molecule. The balance between these hydrophobic and hydrophilic regions determines their physical properties in an aqueous environment. The uses of natural phospholipids as additives are numerous in the food industry (e.g., as emulsifiers), in cosmetics, for industrial uses, and for the pharmaceutical industry, especially in the preparation of drug-delivery systems. U.S. Pat. Nos. 4,086,257, 4,097,502, 4,097,503, 4,145,410 and 4,159,988 disclose various modifications of the polar-head-group region of natural phospholipids which lead to unique and unexpected physical properties.
Further, various derivatives of lecithin are known, such as, for example, oxyalkylated lecithin compounds (see U.S. Pat. Nos. 2,310,679 and 3,085,100), and phosphatidyl-alkanolamine derivatives (see for example U.S. Pat. Nos. 2,801,255, 3,542,820, 3,577,446 and 4,254,115). It is desirable to provide novel synthetic phospholipids, particularly having enhanced, controlled, solubility properties in an aqueous environment.